A
low-temperature, Si-deficient variety of vesuvianite
occurs in porous tetrahedral "achtarandite” pseudomorphs
consisting of hibschite, along the banks of the Wiluy
River, Yakutia, Russia, the type locality.

Wiluite
is a very rare variety of Vesuvianite that
was discovered in 1997 in the Wilui River Valley of
the Eastern-Siberian Region of Russia. It is a very
complex silicate mineral containing calcium, aluminum,
magnesium, iron, titanium and boron in addition to the
basic silicate minerals. Wiluite crystals are usually
well-formed euhedrals of dark green color and are translucent
to opaque.

Wiluite is
only known from two locations, the type locality at
the Vilyui River Basin (Vilui
River Basin; Wilui River Basin), Saha Republic (Sakha Republic;
Yakutia), Eastern-Siberian Region, Russia; and a very minor source at Ariccia, Latium, Italy.